Musculoskeletal Injury Prevalence, Pain Perception, and Physical Activity Level Among Brazilian Strength and Cross-Training Practitioners.

In this study, we sought to determine the prevalence of musculoskeletal injuries, perceived pain, and physical activity level among Brazilian practitioners of strength training (ST) and functional fitness (FF). Participants were 311 men and women who trained in 10 FF training centers and seven ST gyms. Each participant completed surveys of the prevalence of musculoskeletal injuries, their pain perception, and their physical activity level. A chi square test was used to analyze associations between groups and distributions of injuries. When any significant difference was observed, the difference score was analyzed through the adjusted residual values. Fisher's exact test was used to determined the associations between musculoskeletal injury prevalence and training modality (FF and ST) and between musculoskeletal injury prevalence and practice frequency (times/wk). To measure the magnitude of association between variables, the Phi coefficient was calculated for 2x2 associations and Cramer's V was used whenever the distributions were outside this standard. When the dependent variable presented a dichotomous characteristic, an Odds Ratio (OR) was calculated with a confidence interval of 95%. We found a higher musculoskeletal injury prevalence in the axial skeleton (n = 52; 83.88%) in FF practitioners and in the lower limbs of ST practitioners (n = 9; 52.96%). When the physical activity level cutoff point was set at 300 minutes per week, there was a significant relationship between physical activity and training modality (p = 0.005). There was also a significant association between pain perception and musculoskeletal injury (p < 0.001). Clinical follow-up was a protective factor to being injured (OR = 0.18; CI = 0.06-0.49), and, even after multivariate analysis this significant association was maintained (OR = 0.03; CI = 0.01 - 0.08). Thus, FF practitioners reported more musculoskeletal injuries than STs, and follow-up medical or physical therapy was a protective factor to these injuries. FF practitioners also had a higher level of weekly physical activity weekly than ST practitioners. Functional fitness practitioners may be at a higher risk of injuries than those who participate in traditional strength training.

Effects of Different Recovery Modalities on Delayed Onset Muscle Soreness, Recovery Perceptions, and Performance Following a Bout of High-Intensity Functional Training.

The purpose of this study was to investigate the effects of the foam rolling technique and static stretching on perceptual and neuromuscular parameters following a bout of high-intensity functional training (HIFT), which consisted of 100 pull-ups, 100 push-ups, 100 sit-ups, and 100 air squats (Angie benchmark) in recreationally trained men (n = 39). Following baseline measurements (Feeling Scale, Visual Analogue Scale, Total Quality Recovery, Sit-and-Reach, Countermovement Jump, and Change-of-Direction t-test), the volunteers performed a single bout of HIFT. At the end of the session, participants were randomly assigned to one of three distinct groups: control (CONT), foam rolling (FR), or static stretching (SS). At the 24 h time-point, a second experimental session was conducted to obtain the post-test values. The level of significance was set at p < 0.05. Regarding power performance, none of the three groups reached pretest levels at 24 h point of the intervention. However, the CONT group still showed a greater magnitude of effect at the 24 h time-point (ES = 0.51, p ≥ 0.05). Flexibility presented the same recovery pattern as power performance (post × 24 h CONT = ES = 0.28, FR = ES = 0.21, SS = ES = 0.19). At 24 h, all groups presented an impaired performance in the COD t-test (CONT = ES = 0.24, FR = ES = 0.65, SS = ES = 0.56 p ≥ 0.05). The FR protocol resulted in superior recovery perceptions (pre × 24 h TQR = ES = 0.32 p ≥ 0.05). The results of the present study indicate that the use of FR and SS exercises may not be indicated when aiming to restore neuromuscular performance following a single bout of HIFT. The use of the FR technique during the cooldown phase of a HIFT session may be helpful in improving an individual's perception of recovery.

Impact of Different Resistance Training Protocols on Balance, Quality of Life and Physical Activity Level of Older Women.

BACKGROUND: Physical activity (PA) and physical fitness are key factors for quality of life (QoL) for older women. The aging process promotes the decrease in some capacities such as strength, which affect the activities of daily life. This loss of strength leads to a reduction in balance and an increased risk of falls as well as a sedentary lifestyle. Resistance Training (RT) is an effective method to improve balance and strength but different RT protocols can promote different responses. Power training has a higher impact on the performance of activities of daily life. Therefore, our study aimed to analyze if different RT protocols promote individual responses in balance, QoL and PA levels of older women and which are more effective for the older women. METHODS: Ninety-four older women were divided into four RT groups (relative strength endurance training, SET; Traditional strength training, TRT; absolute strength training, AST; power training, PWT) and one control group (CG). Each RT group performed a specific protocol for 16 weeks. At baseline and after 8 and 16 weeks, we assessed balance through the Berg balance scale; PA levels with a modified Baecke questionnaire and QoL with World Health Organization Quality of Life-BREF (WHOQOL-BREF) and World Health Organization Quality of Life-OLD module (WHOQOL-OLD). RESULTS: Balance improved after 16 weeks (baseline vs. 16 weeks; p < 0.05) without differences between all RT groups. PWT (2.82%) and TRT (3.48%) improved balance in the first 8 weeks (baseline vs. 8 weeks; p < 0.05). PA levels increased in PWT, TRT and AST after 16 weeks (baseline vs. 16 weeks; p < 0.05). CONCLUSION: All RT protocols improved PA levels and QoL after 16 weeks of training. For the improvement of balance, QoL and PA, older women can be subjected to PWT, AST and SET, and not be restricted to TRT.

Anodal Transcranial Direct Current Stimulation Increases Muscular Strength and Reduces Pain Perception in Women With Patellofemoral Pain.

ABSTRACT: Rodrigues, GM, Paixão, A, Arruda, T, de Oliveira, BRR, Maranhão Neto, GA, Marques Neto, SR, Lattari, E, and Machado, S. Anodal transcranial direct current stimulation increases muscular strength and reduces pain perception in women with patellofemoral pain. J Strength Cond Res 36(2): 371-378, 2022-The purpose of this study is to investigate the effects of anodic transcranial direct current stimulation applied to motor cortex combined with open kinetic chain exercises on muscular strength and pain perception in women with patellofemoral pain (PFP). Twenty-eight women aged between 18 and 30 years with PFP were selected. Subjects were randomized in 2 groups, anodic stimulus plus resistance training (n = 14; anodic transcranial direct current stimulation [a-tDCS] + RT) or placebo stimulus plus resistance training (n = 14; Sham + RT) and attended the laboratory for 12 experimental sessions, 48-72 hours apart from each other. The RT protocol consisted of 3 sets of 12 repetitions of the knee extension exercise at 60% of 10 maximal repetition (10RM) with a 1-minute interval between sets. In the a-tDCS + RT group, a 2-mA current was applied for 20 minutes over the motor cortex before the RT protocol in each session. In the Sham + RT group, the stimulus was interrupted after 30 seconds. Preintervention, fourth session, eighth session, and postintervention, load was assessed through a 10RM test. The pain perception was assessed through Clarke sign maneuver (CSM) and measured through a visual analogue scale for pain. The a-tDCS + RT group showed greater 10RM load than Sham + RT group at eighth session (p < 0.05) and postintervention (p < 0.05). In a-tDCS + RT group, pain perception reduced in the postintervention compared with preintervention (p < 0.05). The intervention a-tDCS + RT was able to improve muscular strength in women with PFP. In addition, pain perception only decreased postintervention in the a-tDCS + RT group. This combined intervention can be used by coaches in rehabilitation programs aiming to treat PFP through medium-term strength gains.

3,5-Diiodothyronine protects against cardiac ischaemia-reperfusion injury in male rats.

NEW FINDINGS: What is the central question of this study? 3,5-Diiodothyronine (3,5-T2) administration increases resting metabolic rate, prevents or treats liver steatosis in rodent models, and ameliorates insulin resistance: what are its effects on cardiac electrical and contractile properties and autonomic regulation? What is the main finding and its importance? Chronic 3,5-T2 administration has no adverse effects on cardiac function. Remarkably, 3,5-T2 improves the autonomous control of the rat heart and protects against ischaemia-reperfusion injury. ABSTRACT: The use of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) to treat metabolic diseases has been hindered by potential adverse effects on liver, lipid metabolism and cardiac electrical properties. It is recognized that 3,5-diiodothyronine (3,5-T2) administration increases resting metabolic rate, prevents or treats liver steatosis in rodent models and ameliorates insulin resistance, suggesting 3,5-T2 as a potential therapeutic tool. However, a comprehensive assessment of cardiac electrical and contractile properties has not been made so far. Three-month-old Wistar rats were daily administered vehicle, 3,5-T2 or 3,5-T2+T4 and no signs of atrial or ventricular arrhythmia were detected in non-anaesthetized rats during 90 days. Cardiac function was preserved as heart rate, left ventricle diameter and shortening fraction in 3,5-T2-treated rats compared to vehicle and 3,5-T2+T4 groups. Power spectral analysis indicated an amelioration of the heart rate variability only in 3,5-T2-treated rats. An increased baroreflex sensitivity at rest was observed in both 3,5-T2-treated groups. Finally, 3,5-T2 Langendorff-perfused hearts presented a significant recovery of left ventricular function and remarkably smaller infarction area after ischaemia-reperfusion injury. In conclusion, chronic 3,5-T2 administration ameliorates tonic cardiac autonomic control and confers cardioprotection against ischaemia-reperfusion injury in healthy male rats.

Effects of high intensity interval training on neuro-cardiovascular dynamic changes and mitochondrial dysfunction induced by high-fat diet in rats.

BACKGROUND AND AIMS: Mitochondrial swelling is involved in the pathogenesis of many human diseases associated with oxidative stress including obesity. One of the strategies for prevention of deleterious effects related to obesity and overweight is engaging in regular physical activity, of which high intensity interval training (HIIT) is efficient in promoting biogenesis and improving the function of mitochondria. Therefore, our aims were to investigate the effects of HIIT on metabolic and neuro-cardiovascular dynamic control and mitochondrial swelling induced by high-fat diet (HFD). METHODS AND RESULTS: Twenty-three male Wistar rats (60 - 80g) were divided into 4 subgroups: control (C), HIIT, HFD and HFD+HIIT. The whole experimentation period lasted for 22 weeks and HIIT sessions were performed 5 days a week during the last 4 weeks. At the end of the experiments, fasting glucose and insulin tolerance tests were performed. Cerebral microcirculation was analyzed using cortical intravital microscopy for capillary diameter and functional density. Cardiac function and ergoespirometric parameters were also investigated. Mitochondrial swelling was evaluated on brain and heart extracts. HFD promoted an increase on body adiposity (p<0.001), fasting glucose levels (p<0.001), insulin resistance index (p<0.05), cardiac hypertrophy index (p<0.05) and diastolic blood pressure (p<0.05), along with worsened cardiac function (p<0.05), reduced functional cerebral capillary density (p<0.05) and its diameter (p<0.01), and heart and brain mitochondrial function (p<0.001). HFD did not affect any ergoespirometric parameter. After 4 weeks of training, HIIT was able to improve cardiac hypertrophy index, diastolic blood pressure, cerebral functional capillary density (p<0.01) and heart and brain mitochondrial swelling (p<0.001). CONCLUSION: In animals subjected to HFD, HIIT ameliorated both cerebral mitochondrial swelling and functional capillary density, but it did not improve cardiovascular function suggesting that the cardiovascular dysfunction elicited by HFD was not due to heart mitochondrial swelling.

É a estimulação transcraniana de corrente contínua anódica um potencial recurso ergogênico para força muscular e percepção de esforço? Uma revisão crítica / Es la estimulación transcraneal de corriente continua anódica un potencial recurso ergogénico para fuerza muscular y percepción de esfuerzo? Una revisión crítica / Is anodal transcranial direct current stimulation a potential ergogenic resource for muscle strength and effort perception? A critical review

Nas últimas décadas, vários estudos estão investigando a dose-resposta ideal em termos de frequência, intensidade e volume de treinamento para alcançar o aumento da força muscular, tanto em atletas quanto em não atletas. A dose-resposta é fundamental para a prescrição do treinamento, uma vez que sua manipulação equivocada pode acarretar alto risco de desenvolvimento de lesões por esforços repetitivos, bem como pelo não desenvolvimento da força esperada. Em indivíduos com nível avançado de treinamento de força, é extremamente importante aumentar sua intensidade e volume de treinamento. Nesse sentido, com os avanços encontrados na área de treinamento de força e a necessidade de novas estratégias para otimizar ganhos de força, um novo método vem ganhando força na literatura, a estimulação transcraniana por corrente contínua (ETCC). Portanto, o objetivo deste estudo é analisar criticamente os efeitos do ETCC como potencial recurso ergogênico para a realização de força muscular e percepção de esforço, bem como se seu uso é ético ou não. Para tanto, foram pesquisadas as bases de dados Pubmed/Medline, ISI Web of Knowledge e Scielo, apenas em inglês, e com as palavras-chave: força muscular, resistência muscular, estimulação transcraniana por corrente contínua, ETCC. Nós comparamos o efeito do ETCC anódico (ETCC-a) com uma condição sham/controle nos resultados de força muscular e percepção de esforço. Nenhum estudo menciona efeitos colaterais negativos da intervenção. Os dados mostram diferenças entre os estudos que investigam os estudos de avaliação da força muscular e resistência muscular, em termos do uso bem sucedido de ETCC. Estudos que investigaram a eficiência do ETCC na melhora da força muscular demonstraram efeitos positivos do ETCC-a em 66,7% dos parâmetros testados. Amaioria dos dados mostra consistentemente a influência do ETCC-a na força muscular, mas não no desempenho de resistência

En las últimas décadas, diversos estudios están investigando la dosis-respuesta ideal en cuanto a la frecuencia, intensidad y volumen de entrenamiento para alcanzar el aumento de fuerza muscular, sea en atletas y no atletas. La dosis-respuesta es fundamental para la prescripción de entrenamiento, pues su manipulación equivocada puede llevar a un alto de riesgo de desarrollo de lesiones por esfuerzo repetitivo, así como para el no desarrollo de la fuerza esperada. En sujetos con nivel avanzado de entrenamiento de fuerza es extremadamente importante aumentar su intensidad y volumen de entrenamiento. En este sentido, con los avances encontrados en el área de entrenamiento de fuerza y la necesidad de nuevas estrategias para optimizar las ganancias de fuerza, un nuevo método está ganando fuerza en la literatura, la estimulación transcraneal por corriente continua (ETCC). Por lo tanto, el objetivo del presente estudio es analizar de forma crítica los efectos de la ETCC como potencial recurso ergogénico al desempeño de fuerza muscular y percepción de esfuerzo, así como si su uso es ético o no. Por lo tanto, se realizó una búsqueda en las bases de datos Pubmed/Medline, ISI Web of Knowledge y Scielo, solamente en inglés y con las palabras clave: fuerza muscular, resistencia muscular, estimulación transcraneal de corriente continua, ETCC. Comparamos el efecto de la ETCC anódica (ETCC-a) a una condición sham/control sobre los resultados de la fuerza muscular y percepción de esfuerzo. Ningún estudio menciona efectos secundarios negativos de la intervención. Los datos muestran diferencias entre los estudios que investigan la fuerza muscular y los estudios de evaluación de resistencia muscular, en lo que se refiere al uso exitoso de la ETCC. Los estudios que investigan la eficiencia de la ETCC en la mejora de la fuerza muscular demuestran efectos positivos de la ETCC-a en el 66,7% de los parámetros probados. La mayoría de los datos muestran consistentemente influencia de la ETCC-a en la fuerza muscular, pero no en el rendimiento de resistencia

In the last decades, several studies are investigating the optimal dose-response in terms of frequency, intensity and volume of training to achieve increased muscle strength in both athletes and non-athletes. Dose-response is critical to the prescription of training, since its mismanagement may pose a high risk of developing repetitive strain injuries as well as failure to develop the expected strength. In individuals with advanced level of strength training, it is extremely important to increase their intensity and training volume. In this sense, with the advances in the area of strength training and the need for new strategies to optimize force gains, a new method is gaining strength in the literature, the transcranial direct current stimulation (tDCS). Therefore, the purpose of this study is to critically analyze the effects of tDCS as a potential ergogenic resource for achieving muscle strength and perceived exertion, as well as whether its use is ethical or not. To do so, we searched the databases Pubmed/Medline, ISI Web of Knowledgeand Scielo, in English only, and with the keywords: muscle strength, muscular endurance, transcranial direct current stimulation, tDCS. We compared the effect of anodic tDCS (a-tDCS) with a sham/control condition on muscle strength and perceived exertion results. No study mentions the negative side effects of the intervention. The data show differences between studies investigating studies of muscle strength and muscle endurance in terms of the successful use of tDCS. Studies that investigated tDCS efficiency in improving muscle strength demonstrated positive effects of a-tDCS on 66.7% of the parameters tested. Most data consistently show the influence of a-tDCS on muscle strength, but not on resistance performance

Effects of Transcranial Direct Current Stimulation With Caffeine Intake on Muscular Strength and Perceived Exertion.

Lattari, E, Vieira, LAF, Oliveira, BRR, Unal, G, Bikson, M, de Mello Pedreiro, RC, Marques Neto, SR, Machado, S, and Maranhão-Neto, GA. Effects of transcranial direct current stimulation with caffeine intake on muscular strength and perceived exertion. J Strength Cond Res 33(5): 1237-1243, 2019-The aim of this study was to investigate the acute effects of transcranial direct current stimulation (tDCS) associated with caffeine intake on muscular strength and ratings of perceived exertion (RPE). Fifteen healthy young males recreationally trained (age: 25.3 ± 3.2 years, body mass: 78.0 ± 6.9 kg, height: 174.1 ± 6.1 cm) were recruited. The experimental conditions started with the administration of caffeine (Caff) or placebo (Pla) 1 hour before starting the anodal tDCS (a-tDCS or sham). There was an intake of 5 mg·kg of Caff or 5 mg·kg of Pla. After the intake, a-tDCS or sham was applied in the left dorsolateral prefrontal cortex with intensity of 2 mA and 20 minutes of duration. The experimental conditions were defined as Sham + Pla, a-tDCS + Pla, Sham + Caff, and a-tDCS + Caff. After the conditions, muscular strength and RPE were verified. Muscular strength was determined by volume load performed in bench press exercise. Muscular strength in Sham + Pla condition was lower compared with all others conditions (p < 0.05). The RPE in the Sham + Pla was greater compared with a-tDCS + Caff (p < 0.05). Muscular strength was greater in all experimental conditions, and a-tDCS + Caff had lower RPE compared with placebo. When very little gains in muscle strength are expected, both caffeine and tDCS were effective in increasing muscle strength. Besides, the improvement in RPE of the caffeine associated with a-tDCS could prove advantageous in participants experienced in strength training. In fact, coaches and applied sport scientists quantitating the intensity of training based on RPE.

Prediction of cardiorespiratory fitness in the brazilian population aged 20 to 59 years: a non-exercise model approach with self-reported variables / Estimativa da aptidão cardiorrespiratória da população brasileira de 20 a 59 anos: abordagem por meio de modelo sem exercício com variáveis auto-relatadas

ABSTRACT Unlike other more common health-related variables, cardiorespiratory fitness (CRF) is not frequently measured in the general population. This omission characterizes a loss of relevant information. Thus, the objectives of the present study were: a) to characterize the CRF of the Brazilian population aged 20 to 59 years and to develop normative values using a non-exercise equation for predicting maximal oxygen uptake (VO2max), and b) to verify the association between lower levels of CRF and the prevalence of chronic diseases. A total of 32,531 individuals from the National Health Survey (NHS-IBGE-2013) composed the sample. Only self-reported variables were included in the equation of Wier et al. (2006): sex, age, physical activity level, and body mass index. The mean predicted VO2max was 44.6, 39.3, 34.8 and 30.6 ml/kg/min for men, and 34.5, 29.6, 25.4 and 21.1 ml/kg/min for women aged 20-29, 30-39, 40-49 and 50-59 years, respectively. The 20th and 80th percentiles were established as the extremes (very low and very high CRF). Participants with low fitness had a 33% higher chance of cardiovascular disease, an 89% higher chance of diabetes mellitus, and a 67% higher chance of hypertension, regardless of sex, age and presence of obesity, which seem to corroborate the quality of the equation.

RESUMO Diferentemente de outras variáveis mais comuns relacionadas à saúde, a aptidão cardiorrespiratória (ACR) não é medida constantemente na população em geral. Sua omissão caracteriza numa perda de informação relevante. Com isso os objetivos do presente estudo foram: a) caracterizar a ACR da população brasileira de 20 a 59 anos, desenvolvendo valores normativos através de uma equação para estimar o consumo máximo de oxigênio (VO2Máx) sem a realização de exercícios; e b) verificar a associação de menores níveis de ACR com a prevalência de doenças crônicas. Ao todo, 32.531 indivíduos compuseram a amostra oriunda da Pesquisa Nacional de Saúde (PNS-IBGE-2013). Apenas variáveis auto-relatadas foram incluídas a partir da equação de Wier et al. (2006): sexo, idade, nível de atividade física e Índice de Massa Corporal. A média de VO2Máx foi estimada como 44,6; 39,3; 34,8 e 30,6 ml/kg/min (homens) e 34,5; 29,6; 25,4 e 21,1 ml/kg/min (mulheres) com idades 20-29; 30-39; 40-49 e 50-59. Os valores de percentil 20 e 80 foram estabelecidos como os extremos de muito baixa e muito alta ACR. A baixa aptidão demonstrou significativamente 33% maiores chances de prevalência de doença cardiovascular, 89% de diabetes mellitus e 67% de hipertensão arterial independentemente de sexo, idade, e presença de obesidade, o que parece corroborar a qualidade da equação utilizada.

Determination of heart rate threshold from heart rate kinetics during maximal graded exercise in soccer players / Determinação do limiar da frequência cardíaca a partir da cinética da frequência cardíaca durante o exercício graduado máximo em jogadores de futebol

Abstract The main of the present study was to identify the heart rate threshold based on heart rate kinetics during graded maximal exercise in football players. Twenty-six male football players performed a maximal exercise test (Bruce protocol) on a motor-driven treadmill. Oxygen uptake (VO2) and heart rate (HR) were monitored, recorded and resampled at 3.5Hz. The ventilatory threshold (VT), and respiratory compensation (RC), heart rate deflection points (HRDP1 and HRDP2) and heart rate kinetics threshold (HRT) were determined by computerized methods. The heart rate variability (HRV) was assessed in the frequency domain. The HRT averaged 89.9 ± 1.2 % of the VO2 peak. The HRT showed poor correlations and significant differences compared with HRDP1 (r = 0.46) and VT (r = 0.51), but was not different from, and highly correlated with, HRDP2 (0.98) and RC (0.90). Bland Altman plots showed all athletes into 95% of limits of agreement, and intraclass correlation coefficient showed good agreements between points obtained from HRT compared with HRDP2 (0.96) and RC (0.98). The HRT was highly correlated with HRDP2 and RC, suggesting it could be a marker for cardiorespiratory fatigue.

Resumo O objetivo do presente estudo foi identificar o limiar de frequência cardíaca baseado na cinética da frequência cardíaca durante o exercício máximo graduado em jogadores de futebol. Vinte e seis jogadores de futebol masculino realizaram um teste de exercício máximo (protocolo de Bruce) em uma esteira motorizada. O consumo de oxigênio (VO2) e a freqüência cardíaca (FC) foram monitorados, registrados e reamostrados a 3,5Hz. O limiar ventilatório (LV), a compensação respiratória (CR), os pontos de deflexões da frequência cardíaca (PDFC1 e PDFC2) e o limiar da cinética da frequência cardíaca (LCFC) foram determinados por métodos computadorizados. A variabilidade da frequência cardíaca (VFC) foi avaliada no domínio da frequência. A média do LCFC foi de 89,9 ± 1,2% do VO2 de pico. O LCFC demonstrou correlações e diferenças significativas em relação ao PDFC1 (r = 0,46) e ao LV (r = 0,51), mas não foi diferente e altamente correlacionado com PDFC2 (0,98) e CR (0,90). Os gráficos de Bland Altman mostraram todos os atletas em 95% dos limites de concordância, e o coeficiente de correlação intraclasse apresentou boas concordâncias entre os pontos obtidos com o LCFC em comparação com o PDFC2 (0,96) e CR (0,98). A LCFC foi altamente correlacionada com PDFC2 e CR, sugerindo que poderia ser um marcador de fadiga cardiorrespiratória.

Acute effects of single dose transcranial direct current stimulation on muscle strength: A systematic review and meta-analysis.

Previous studies investigating the effects of transcranial direct current stimulation (tDCS) on muscle strength showed no consensus. Therefore, the purpose of this article was to systematically review the literature on the effects of single dose tDCS to improve muscle strength. A systematic literature search was conducted on PubMeb, ISI Web of Science, SciELO, and Scopus using search terms regarding tDCS and muscle strength. Studies were included in accordance with Population, Intervention, Comparison, Outcomes, and Setting (PICOS) including criteria. Healthy men and women, strength training practitioners or sedentary were selected. The acute effects of single dose anode stimulus of tDCS (a-tDCS) and the placebo stimulus of tDCS (sham) or no interventions were considered as an intervention and comparators, respectively. Measures related to muscle strength were analyzed. To conduct the analyses a weighted mean difference (WMD) and the standardized mean difference (SMD) were applied as appropriate. A total of 15 studies were included in this systematic review and 14 in meta-analysis. Regarding the maximal isometric voluntary contraction (MIVC), a small effect was seen between tDCS and Sham with significant difference between the conditions (SMD = 0.29; CI95% = 0.05 to 0.54; Z = 2.36; p = 0.02). The muscular endurance measured by the seconds sustaining a percentage of MIVC demonstrated a large effect between tDCS and Sham (WMD = 43.66; CI95% = 29.76 to 57.55; Z = 6.16; p < 0.001), showing an improvement in muscular endurance after exposure to tDCS. However, muscular endurance based on total work showed a trivial effect between tDCS and Sham with no significant difference (SMD = 0.22; CI95% = -0.11 to 0.54; Z = 1.32, p = 0.19). This study suggests that the use of tDCS may promote increase in maximal voluntary contraction and muscular endurance through isometric contractions.

Prediction of cardiorespiratory fitness from self-reported data in elderly / Predição da aptidão cardiorrespiratória através de dados auto-relatados em idosos

Abstract Cardiorespiratory fitness (CRF) is associated with several health outcomes. Some non-exercise equations are available for CRF estimation. However, little is known about the validation of these equations among elderly. The aim of this study was to exam the validity of non-exercise equations with self-reported information in elderly. Participants (n= 93) aged 60 to 91 years measured CRF using maximal cardiopulmonary exercise test. Five non-exercise equations were selected. Data included in the equations (age, sex, weight, height, body mass index, physical activity and smoking) were self-reported. Coefficient of determination (R2) of linear regressions with laboratory-measured VO2 peak ranged from 0.04 to 0.64. The Bland-Altman plots showed higher agreement between achieved and predicted CRF obtained by Jackson and colleagues, and Wier and colleagues equations. On the other hand, the other equations showed lower agreement and overestimation. Our findings provide evidences that two non-exercise equations, previously developed, could be used on the prediction of CRF among elderly.

Resumo A aptidão cardiorrespiratória (ACR) está associada a vários desfechos de saúde. Algumas equações sem exercício estão disponíveis para estimar a ACR. No entanto, pouco se sabe sobre a validação dessas equações entre os idosos. Objetivo: O estudo foi desenvolvido com o objetivo de examinar a validade de equações sem exercício com informações auto-relatadas em idosos. Métodos: Os participantes (n = 93) com idades entre 60 e 91 anos foram submetidos ao teste de exercício cardiopulmonar máximo para avaliar a ACR. Cinco equações sem exercício foram selecionadas. Os dados incluídos nas equações (idade, sexo, peso, altura, índice de massa corporal, atividade física e tabagismo) foram auto-relatados. Resultados: O coeficiente de determinação (R2) das regressões lineares com o VO2 pico, medido em laboratório, variou de 0,04 a 0,64. Os gráficos de Bland-Altman mostraram maior concordância entre a ACR obtida e prevista por Jackson e colaboradores, e equações de Wier e colaboradores. Por outro lado, as demais equações mostraram menor concordância e superestimação. Conclusões: Nossos resultados fornecem evidências de que duas equações sem exercício, previamente desenvolvidas, poderiam ser usadas na estimação da ACR em idosos.

Vascular and Inflammatory Acute Responses after a Resistance Exercise Session in Young Women with Excessive Adiposity / Respostas vasculares e inflamatórias agudas depois de uma sessão de exercício resistido em mulheres jovens com excesso de adiposidade

BACKGROUND: Endothelial dysfunction and low-grade inflammation are both positively associated to states of excessive adiposity but reports on the acute effects of resistance exercise on these variables are still lacking. We evaluated these acute effects of resistance exercise on vascular reactivity and on the inflammatory profile in young women. METHODS: Participants were divided into two groups: lean Controls (n=16) and Overweight (n=16). The resistance exercise session consisted of unilateral elbow flexions for five sets of 10 repetitions at 70% of one repetition maximum. Blood pressure, heart rate, forearm blood flow, vascular conductance, cytokines, adipopeptides and endothelin-1 were evaluated at rest and during the acute post-exercise period. RESULTS: The overweight group had higher forearm blood flow at rest (p=0.03) and during post-exercise (p<0.001) while forearm vascular conductance was higher only during post-exercise, at 20 (p=0.02) and 40 min (p<0.001). Endothelial-dependent vasodilation was higher during the post-exercise period in the Overweight group compared to controls (p=0.01). In the Overweight group, the resistance exercise session reduced interleukin-6 (p=0.02) and leptin (p<0.001) but increased endothelin-1 levels (p=0.02). CONCLUSIONS: We conclude that the single resistance exercise session elicited an acute increment of baseline vascular reactivity and an increased endothelial-dependent vasodilation with concomitant changes in inflammatory profile and endothelin-1 in our tested women with excessive adiposity.

ANTECEDENTES: A disfunção endotelial e a inflamação de baixo grau estão positivamente associadas a estados de adiposidade excessiva; entretanto os efeitos agudos do exercício resistido sobre estas variáveis ainda não estão esclarecidos. Avaliamos os efeitos agudos do exercício resistido sobre a reatividade vascular e sobre o perfil inflamatório em mulheres jovens. MÉTODOS: As participantes foram divididas em dois grupos: controles magras (n = 16) e aquelas com sobrepeso (n = 16). A sessão de exercício resistido consistiu de flexões unilaterais de cotovelo em cinco séries de 10 repetições (com 70% de uma repetição máxima). Avaliamos tanto no repouso quanto durante o período pós-exercício agudo a pressão arterial, a frequência cardíaca, o fluxo sanguíneo do antebraço (FBF) e a condutância vascular (CVF), as citocinas, os adipopeptídeos e a endotelina-1. RESULTADOS: O grupo com sobrepeso apresentou maior FBF em repouso (p = 0,03) e pós-exercício (p <0,001), enquanto a CVF foi maior somente após o exercício, aos 20 min (p = 0,02) e aos 40 min (p <0,001) . A vasodilatação endotélio-dependente durante o período pós-exercício foi maior no grupo Overweight em relação aos controles (p = 0,01). No grupo Overweight, a sessão de exercício resistido reduziu a interleucina-6 (p = 0,02) e a leptina (p <0,001) e o aumentou os níveis de endotelina-1 (p = 0,02). CONCLUSÃO: Concluímos que a sessão de exercício resistido provocou um incremento agudo da reatividade vascular basal e um aumento da vasodilatação endotélio-dependente com alterações concomitantes no perfil inflamatório e da endotelina-1 em mulheres com adiposidade excessiva.

Normalizing handgrip strength in older adults: An allometric approach.

PURPOSE: Handgrip strength is an important variable to assess as part of any health intervention among older adults. Although the use of allometric normalization is the appropriate approach for removing the body size effect in handgrip performance, the best body size variable for this normalization is still unclear. Therefore, the aim of the present study was to compare the use of three body size variables (body mass, fat-free mass and body height) in allometric normalization for Handgrip strength among older adults. METHODS: Data from individuals admitted to the Elderly Care Center of the Open University of the Third Age were used, the sample consisting of 263 individuals (140 women), aged between 60-87. RESULTS: The results provided allometric exponents for normalization of HGS in each body size variable (body mass: 0.31; fat-free mass: 0.11; body height: 0.46). The correlations between normalized HGS and body size variables were significant (p<0.05) when HGS were normalized by body mass or fat-free mass. On the contrary, no significant correlations were found when HGS were normalized by body height. CONCLUSIONS: Body height seems to be the best body size variable for performing allometric normalization of HGS among older adults.

Effects of Incretin-Based Therapies on Neuro-Cardiovascular Dynamic Changes Induced by High Fat Diet in Rats.

BACKGROUND AND AIMS: Obesity promotes cardiac and cerebral microcirculatory dysfunction that could be improved by incretin-based therapies. However, the effects of this class of compounds on neuro-cardiovascular system damage induced by high fat diet remain unclear. The aim of this study was to investigate the effects of incretin-based therapies on neuro-cardiovascular dysfunction induced by high fat diet in Wistar rats. METHODS AND RESULTS: We have evaluated fasting glucose levels and insulin resistance, heart rate variability quantified on time and frequency domains, cerebral microcirculation by intravital microscopy, mean arterial blood pressure, ventricular function and mitochondrial swelling. High fat diet worsened biometric and metabolic parameters and promoted deleterious effects on autonomic, myocardial and haemodynamic parameters, decreased capillary diameters and increased functional capillary density in the brain. Biometric and metabolic parameters were better improved by glucagon like peptide-1 (GLP-1) compared with dipeptdyl peptidase-4 (DPP-4) inhibitor. On the other hand, both GLP-1 agonist and DPP-4 inhibitor reversed the deleterious effects of high fat diet on autonomic, myocardial, haemodynamic and cerebral microvascular parameters. GLP-1 agonist and DPP-4 inhibitor therapy also increased mitochondrial permeability transition pore resistance in brain and heart tissues of rats subjected to high fat diet. CONCLUSION: Incretin-based therapies improve deleterious cardiovascular effects induced by high fat diet and may have important contributions on the interplay between neuro-cardiovascular dynamic controls through mitochondrial dysfunction associated to metabolic disorders.

AT1 and aldosterone receptors blockade prevents the chronic effect of nandrolone on the exercise-induced cardioprotection in perfused rat heart subjected to ischemia and reperfusion.

PURPOSE: Myocardial tolerance to ischaemia/reperfusion (I/R) injury is improved by exercise training, but this cardioprotection is impaired by the chronic use of anabolic androgenic steroids (AAS). The present study evaluated whether blockade of angiotensin II receptor (AT1-R) with losartan and aldosterone receptor (mineralocorticoid receptor, MR) with spironolactone could prevent the deleterious effect of AAS on the exercise-induced cardioprotection. METHODS AND RESULTS: Male Wistar rats were exercised and treated with either vehicle, nandrolone decanoate (10 mg/kg/week i.m.) or the same dose of nandrolone plus losartan or spironolactone (20 mg/kg/day orally) for 8 weeks. Langendorff-perfused hearts were subjected to I/R and evaluated for the postischaemic recovery of left ventricle (LV) function and infarct size. mRNA and protein expression of angiotensin II type 1 receptor (AT1-R), mineralocorticoid receptor (MR), and KATP channels were determined by reverse-transcriptase polymerase chain reaction and Western blotting. Postischaemic recovery of LV function was better and infarct size was smaller in the exercised rat hearts than in the sedentary rat hearts. Nandrolone impaired the exercise-induced cardioprotection, but this effect was prevented by losartan (AT1-R antagonist) and spironolactone (MR antagonist) treatments. Myocardial AT1-R and MR expression levels were increased, and the expression of the KATP channel subunits SUR2a and Kir6.1 was decreased and Kir6.2 increased in the nandrolone-treated rat hearts. The nandrolone-induced changes of AT1-R, MR, and KATP subunits expression was normalized by the losartan and spironolactone treatments. CONCLUSION: The chronic nandrolone treatment impairs the exercise-induced cardioprotection against ischaemia/reperfusion injury by activating the cardiac renin-angiotensin-aldosterone system and downregulating KATP channel expression.

Analysis of heart rate deflection points to predict the anaerobic threshold by a computerized method.

Many studies have used the heart rate deflection points (HRDPs) during incremental exercise tests, because of their strong correlation with the anaerobic threshold. The aim of this study was to evaluate the profile of the HRDPs identified by a computerized method and compare them with ventilatory and lactate thresholds. Twenty-four professional soccer players (age, 22 ± 5 years; body mass, 74 ± 7 kg; height 177 ± 7 cm) volunteered for the study. The subjects completed a Bruce-protocol incremental treadmill exercise test to volitional fatigue. Heart rate (HR) and alveolar gas exchange were recorded continuously at ≥1 Hz during exercise testing. Subsequently, the time course of the HR was fit by a computer algorithm, and a set of lines yielding the lowest pooled residual sum of squares was chosen as the best fit. This procedure defined 2 HRDPs (HRDP1 and HRDP2). The HR break points averaged 43.9 ± 5.9 and 89.7 ± 7.5% of the VO2peak. The HRDP1 showed a poor correlation with ventilatory threshold (VT; r = 0.50), but HRDP2 was highly correlated to the respiratory compensation (RC) point (r = 0.98). Neither HRDP1 nor HRDP2 was correlated with LT1 (at VO2 = 2.26 ± 0.72 L·min(-1); r = 0.26) or LT2 (2.79 ± 0.59 L·min(-1); r = 0.49), respectively. LT1 and LT2 also were not well correlated with VT (2.93 ± 0.68 L·min(-1); r = 0.20) or RC (3.82 ± 0.60 L·min(-1); r = 0.58), respectively. Although the HR deflection points were not correlated to LT, HRDP2 could be identified in all the subjects and was strongly correlated with RC, consistent with a relationship to cardiorespiratory fatigue and endurance performance.

Influência da intensidade e do volume do treinamento resistido no comportamento autonômico cardíaco / Influence of intensity and volume of strength training on autonomic cardiac system behavior

Fundamentos: Devido às diferentes variáveis relacionadas ao treinamento resistido, os seus efeitos sobre o controle autonômico ainda são desconhecidos. Objetivo: Verificar os efeitos agudos de distintas intensidades de exercício resistido [6 vs 12 repetições máximas (RM)] no comportamento autonômico cardíaco durante treino de força composto por seis exercícios. Métodos: 10 voluntários (idade 27,5 +-5,6 anos; massa corporal 81,6 +- 26,9kg; estatura 177,6 +- 11,8cm; IMC 24,45 +- 6,7kg/m²) participaram do estudo e realizaram seis exercícios com 6RM e 12RM. A variabilidade da frequência cardíaca (VFC) foi obtida a partir dos intervalos de pulso (iRR) coletados aos 10min pré e pós-esforço. No domínio do tempo, foram calculados...

Resposta autonômica cardíaca e cardiorrespiratória em atletas de voleibol versus indivíduos treinados / Autonomic cardiac and cardiorespiratory responses in volleyball athletes compared to trained individuals

Fundamentos: Durante exercício progressivo descreve-se a redução da variabilidade da frequência cardíaca (VFC) e, no período pós-exercício, o comportamento da VFC parece depender de variáveis como duração, tipo e intensidade do estímulo. Objetivo: Investigar e comparar a modulação autonômica cardíaca, através da análise da VFC, em atletas e indivíduos treinados. Métodos: 14 indivíduos saudáveis do sexo masculino, estratificados em dois grupos : Atletas (AT) (n=7; 24,5 +- 7,6 anos; 76,2 +- 9,2kg; 24,5 +- 5,5kg/m²...